Unlimited data plans are an endangered species nowadays, so most of us have to watch our limits in order to avoid excess charges on our bill. That's easy enough when we know how much cellular data we're using on our smartphones, but becomes problematic when our smartphones eat up our precious megabytes in the background. This doesn't just happen on Android, but iPhone, too. Here's how to stop it.

Recently, a friend asked me for help when he reached 90% of his data usage despite barely using any data. I thought this was surprising because he has an iPhone and iPhones aren't allowed to do a whole lot in the background. Despite these limitations, apps can still do a fair amount of downloading when they're not open and regardless of how they're connected to the internet. In short, you could end up going over your data limits easily without even knowing it, regardless of whether you're on Android or iPhone. In this post we're going to look at how to figure out which apps are eating your data unnecessarily and how to stop them. On Android it's pretty simple, but for iPhone you need to do a little detective work.

Android

Tracking which apps use your data is pretty simple. Just install My Data Manager (Free) and allow it to track the data your apps use. At any time, you can open up Data Manager and take a look at how many megabytes (or gigabytes) any app is using. If anything is sucking your data plan dry, make sure that app isn't running in the background (or just delete it from your phone altogether). Solving the problem is easy so long as you know which app is using up all of your data.

iPhone

On an iPhone, you can't track exactly which apps are using your data unless you're jailbroken. If you are, you can grab iNetUsage ($2) from Cydia and monitor the breakdown. If not, you need to conduct an investigation and find the culprit(s) with some trial and error. Let's go over a few methods.

Ensure Wi-Fi Is Actually Enabled

Sometimes high data usage happens because you turned off Wi-Fi and just forgot. When my internet access goes down, I often do this and forget to turn it back on for a week. Fortunately I just don't use that much data in general, but if I did it could turn into a major problem. Before you spend a bunch of your time investigating the problem, make sure your data settings are actually correct.

Look at the Apps that Use the Most Battery

On an iPhone, if an app is draining your battery it has a better chance of eating up your data plan as well. Battery-sucking apps run in the background, and there are only a few things background apps can do on an iPhone: use the GPS, play music, and download files. While apps that download files might seem like guilty party, iOS only allows background downloading for a short amount of time. If the app isn't open on your phone, iOS will shut off its download privileges after about 10 minutes. As a result, you're probably aware of when an app is downloading something in the background.

You're more likely to run into wasted data when you leave a music or location-aware app open in the background. Music apps can play indefinitely, and if they're streaming that music you can use a lot of data simply by forgetting to stop playback. Location-aware apps use your GPS and may need to download data relevant to that GPS. While it's unlikely that they're constantly grabbing new data (e.g. maps or location-based photos), you want to be sure these kind of apps aren't accessing your location without your knowledge. Fortunately, this is very easy to do. Simply go into the Settings app on your iPhone, tap Privacy (in iOS 6, Location Services in earlier versions), then tap Location Services, and peruse the list of apps. Most apps will just have an ON and OFF switch, but some will have a purple solid, purple outline, or gray solid arrow next to them. A purple arrow means the app has used your location recently, a gray arrow indicates the app has used your location in the last 24 hours, and a purple outline arrow indicates the app is using a geofence (meaning that it's waiting to carry out an event when you're in a certain location, like when the Reminders app provides a location-based reminder). The purple solid and outline arrows are the ones that cause the most trouble, so if you see them, try quitting those apps to see if your data usage decreases.

Check Your Bill

Most cellular providers keep detailed records of your data usage, even if it's only temporary. Whether or not your bill will retain enough detail to tell you what you were doing with that data is another story, but it will tell you how much you used on a specific day and time. In the event you forgot about a large download, or you retrieved a lot of data that you thought was over Wi-Fi, you may be able to pinpoint the cause by knowing exactly when it happened.

Additionally, you may be able to find out more detailed information by calling your cellular provider directly. They may have access to more information than you, and they may be able to add something called "detailed billing" to your plan. This service often costs money but provides additional information about your data usage so you know what's going on. That said, signing up for this service means you're paying your provider to keep a record of what you do on your smartphone that they may retain longer than the data they already keep about you. Consider whether that matters to you before signing up.

Employ a Data Monitoring App and Use It Strategically

If you'd prefer to avoid your cellular provider, you can also use a data monitoring app to keep an eye on your overall usage. This won't tell you which app is causing trouble, but it will tell you when a lot of data was used. Just like you can with your bill (as discussed in the previous section), you can use the date and time information to try and pinpoint what happened when large amounts of data was consumed. Sure, this isn't a definitive method but it might help you zero in on the culprit(s).

The iPhone isn't lacking in data usage trackers, but many of them offer few features or do…
Read more Read more

Call Your Cellular Provider

Wasted data may not be your fault—it may be an error on the part of your provider. Don't just assume it's your fault. Chances are you did use the data, but sometimes mistakes happen (nobody's perfect, after all). If you've looked around and something seems a little fishy, call your provider and ask. There may be an error and you may be in the clear.